Collaboration Teams - Members share responsibility for posting refined answers to the guided readings - succinct, relevant, clear, and with pictures or a video to compliment.
When contributing to the reading guide, follow these steps: 1) First complete the reading guide on your own from the Cell unit page. 2) Write your response to a question in word and then copy it.Be sure to upload pictures and/or video for each question. 3) Click on the edit button and then go to the appropriate question and paste your answer below it. Sign your contribution with your first name and last initial and TEAM COLOR 4) Save the page by selecting "Save with " from the Save dropdown. Enter a comment (e.g. "I answered chp 26 question 3" - Tom S.) then click Save.
Blue
Purple
Green
Pink
Yellow
Orange
Red
2, 6a-b
3, 6c-d
4, 6e-f
5, 6g-h
6i-k
6L-m
6n-o
2. How does an electron microscope work and what is the difference between a scanning and transmission electron microscope?
the electron microscope (EM) focuses a beam of elcetrons through the speciemen or onto the surface. the resolution is invrersley related to the wavelength of the radiation a microscope uses for imaging. an electron beam has a shorter wavelenght then visible light, and can achieve a resolution of .002 nm, which means it can see as small as a carbon atom. SEM and TEM are useful for detailed study of the specimens' surface. the scanning electron mircroscope scans the specimen, which is usually covered in gold layer, and it then takes a image of the topography of it. the SEM has a great depth field and the image appears in 3 dimentional, while the transmission microscope can be used for more photographic film, or viewing on a screen.
Alecia Seliga
3. Describe the process and purpose of cell fractionation.
The goal of cell fractionation is to take cells apart and separate the major organelles from one another. The centrifuge is used to do this. It enables the researcher to prepare specific components of cells in bulk quantity to study their composition and functions.
Ryan H
4. Label the prokaryotic cell below – list structure and function.
Pili - Attachment structure on the surface of some prokaryotes. Nucleoid - Region where the cell's DNA is located (not enclosed). Ribosomes - organelles that synthesize proteins. Plasma Membrane - Membrane enclosing the cytoplasm. Capsule - Jelly-like outer coating of many prokaryotes. Flagella - Locomotion organelles of some bacteria. (Sperm)
- Chris Asimos
5. Why is surface area to volume such an important concept as it applies to the size of a cell?
Huh? Own words Please!
There is a correlation between size and function. The area is proportional to a linear dimension squared, compared to the volume which is proportional to the linear demension cubed. The smaller it is, the greater the ratio of surface area to volume. Each organelle is the correct size for the cell and the organell's task.
Tyler H
6. For each of the structures below – note the specific structure and the function of the organelle or part of the organelle. The important concept is to note how the specific structure allows for the specific function to be accomplished. Include a picture/video for each a. Nucleus: The nucleus is the center of the cell which holds the majority of the genes and DNA of each cell. -Sam B
i. Nuclear envelope: The nuclear envelope of the cell has a double membrane which encloses the nucleus. The nuclear envolpe is covered in pores to allow certain substances in and out of the nucleus. It is continuous with the endoplasmic reticulum. -Sam B ii. Nuclear lamina: The nuclear lamina is a netlike string of proteins filamentsthat maintain the shape of the nucleus. The lamina mechanically supports the nuclear envelope with its structure. -Sam B
iii. Chromosomes: Chromosomes are discrete, distinct units of DNA that carry genetic information. They are made up of chromatin, neatly packaged into specific orders. -Sam B iv. Chromatin- the complex of DNA and protein that makes up a eukaroyotic chromosome. when the cell is not dividing, chromatin exists as a mass of very long thin fibers that are not visible with a light microcope. Alecia Seliga
v. Nucleolus: The nucleolus is a mass of densely stained granules and fibers adjoining part of the chromatin. The nucleolis is the dense center of the nucleus physically holding the majority of the genes of the cell. -Sam B
6 b. Ribosomes: Ribosomes are molecules made up of chromosomal DNA and proteins. They carry out all protein synthesis for cells. Cell that require many proteins will have many ribosomes in order to spread out the task of each ribosome, and create efficient, productive proteins within each cell for their specific function. -Sam B
6 c. Endoplasmic reticulum- It is a network of membrane that accounts for more than half of the eukaryotic cells. It has membranous tubules and cisternae, which are sacs that serve as a “reservoir for substances.” It is continuous with the nuclear envelope.
i. Smooth ER- The surface of the Smooth ER lacks ribosomes. -Some of the metabolical processes that the Smooth ER is part of are the making of lipids. Some lipids that the SER makes are oils, phosphates, and steroids. - It is also part of the metabolism of carbohydrates. - It is also part of the detoxification of drugs and poisons. A Hydroxyl group is added in order to make it more soluble. The liver cells would have more SER. -In muscle cells the Smooth ER stores calcium.
- Fernanda R.
ii. Rough ER is an interconnected system of tubules and vesicles within eukaryotic cells. Its surface is full of ribosomes. The Rough ER synthesizes proteins and then ships them out through transport vesicles.
Ashley A 6 d. Golgi Apparatus (looks like the ER) The Golgi processes proteins from the ER mainly through glycosylation (adding sugar to the proteins). They are packaged through secretory vesicles to their destination.
These proteins will most likely be used in the plasma membrane, in lysosomes, or secreted by digestive enzymes.
Ashley A
6 e. Lysosomes are sacs that contain enzymes at high pH levels. When an organelle in the cell gets damaged, a vesicle is placed around it and the lysosomes merge with that vesicle and recycle the organelle. The same occurs when a food vacuole is introduced to the cell. If too many lysosomes break open in a cell by accident, the cell will digest itself completely.
-Josh S.
6 f. Vacuoles – A vacuole is a membrane bound organelle. It is present in plant and fugal cells and in some protest, animal and bacterial cells
Food – food vacuoles fuse with a lysosome whose enzymes digest the food. The vacuoles carry out hydrolysis and are formed by phagocytosis.
Contractile- pump access water out of the cell to maintain the appropriate concentration of alts in other molecules
Central w/tonoplast- Tonoplasts are enclosed by the membrane. The central vacuole develops by the coalescence of smaller vacuoles. They derived from the ER and the Golgi app. It is an integral part of a plant cells endomembrane system
- Katie Halbruner :) 6 g. Endomembrane system – overall It is complex and dynamic. It is in the cell's compartimental organization and flow of membrane lipids and proteins through the various organelles. Tyler H
6 h. Mitochondria
Only the most important organelle...
i. Mitochondrial matrix ii. Cristae
6
i. Plastids- A family of closely related plant organelles.
i. Amyloplast- Colorless plastids that store starch (amylose), particularly in rods and tubers.
ii. Chromoplast- Have pigments that give fruit and flowers their orange and yellow hues. They also contain green pigment called chlorophyll.
iii. Chloroplast (thylakoids & stroma) - Found only in plant cells. They are sites of photosynthesis where converts solar energy to chemical energy by absorbing sunlight. Thylakoids are flattened membrane sacs inside chloroplast used to convert light energy to chemical engery. The stroma is the fluid of the chloroplast surrounding the thylakoids membrane; it is involved in the synthesis of organic molecules from carbon dioxide and water.
-Mike G
6 j. peroxisomes
An organelle with various specialized metabolic functions. It produces hydrogen peroxide.
-Mike G
6 k. cytoskeleton – pay careful attention to the details in this section
A network of fibers extending throughout the cytoplasm. It plays an important role in organizing the structures and activites of the cell. It is composed of three types of molecular structures: Microtubules, Microfilaments, and Intermediate Filaments.
-Mike G
i. microtubules- Hollow tubes that maintain cell shape, cell mobility, chromosome movement in cell division, organelle movement.
1. centrosomes- microtubles grow out of them, located near the nucleus, responsible for compression and resistance.
centrioles- 9 sets of triple microtubules arranged in a ring, used in cellular division and cell organization
2. cilia- many short hair like structures, move like oars
flagella- few long hair like structures, move together in the same direction
basal body- base of the cilia and flagella grows out of centrioles
3. dynein walking- Large protein, made up of polypeptides, cause the bending movement of cilia and flagella, powered by ATP.
ii. microfilaments- are solid rods about 7nm in diameter present in all eukaryote cells, they bear tension, help support shape, transports materials across the plasma membrane and cell mobility.
1. actin- globular protein
in the cell:
muscle contraction
cell mobility
cell division
2. myosin- protein that acts as a motor protein by beams of projection (arms) that "walk" along the actin filaments, causes cell contraction.
3. pseudopodia- extends and contracts through the reversible assembly of actin subunits into micro filaments.
4. cytoplasmic streaming- Circular flow of cytoplasm within a cell, speeds the distribution of materials within the cell.
iii. intermediate filaments-large in diameter, specialized for bearing tension located in the cytoskeleton.
Taihlor C 6 L.
Cell walls- Cell walls are extracellular structures of plant cells, which seperate them from animal cells. Cell walls help to protect the plan cell, maintain its shape and prevent excess uptake of water.
i. Primary cell wall- (Young plants) A primary cell wall is located just beyond the plasma membrane; it is a flexible extracellular matrix.
ii. Middle lamella- Composed of sticky polysaccharides called pectins. Middle lamella is intercellular material which is between primary walls of adjacent cells.
iii. Secondary cell wall- (Adult plants) A secondary cell wall is located between the primary cell wall and the plasma membrane. It contains several laminated layers including a durable matrix for protection and support. Mostly made from cellulose.
-Dahlia M
6M a. Extracellular matrix- a.k.a. E.C.M. A layer outside of animal cells rich in glycoproteins. Constant source of proteins for cells.
i. Collagen- glycoprotein that makes strong fibrous layer around the cell.
ii. Proteoglycans- weaving glycoproteins that support collagen. Mostly made of sugars.
iii. Fibronectin- glycoprotein that binds the cell to the E.C.M.
iv. Integrins- receptors in the cell membrane that the fibronectins attach to. Act like anchors on a ship: hold the E.C.M. in place. Attach to cytoskeleton on the other side. Takes in information from E.C.M. and send it to the cell.
Below: The horrors of collagen abuse :O
The ECM
Sam V. 6 n. What are intercellular junctions and why are they important?
Intercellular junctions are tight junctions, desmosomes, and gab junctions. They are important because they keep cells together like a lock.
-Amy D 6 o. Contrast plasmodesmata, tight junctions, desmosomes, and gap junctions.
Sounds like wiki speak to me. Can you revise using own words?
Plasmodesmata are channels contained within the plant cell wall. Cytosol to pass through the plasmodesmata and connect the chemical environments of adjacent cells, unifying most of the plant into one living continuum. Water and mall solutes can from one cell to the other using these channels. Tight junctions prevent fluid from moving across a layer of cells. At tight junctions, the membrane of neighboring cells are very tightly pressed against each other, preventing leakages.
-Alina Dyak
PLASMODESMATA
TIGHT JUNCTIONS
-Alina Dyak
The idea of desmosomes is like the glue that holds cells together, they fasten the cells together. This is like a cell to cell adhesion to one of each other, a way to think about it is from the greek meaning “desmos” means band, and “soma” means body, so the two cell bodies are banded together by desmosomes. Whereas gap junctions leave a space in between for the sharing of the cells, they use cytoplasmic channels adjacent from the other cell. With the use of the cytoplasmic connections allows for ions and molecules to pass freely from cell to cell. -Brett Sutow
When contributing to the reading guide, follow these steps:
1) First complete the reading guide on your own from the Cell unit page.
2) Write your response to a question in word and then copy it. Be sure to upload pictures and/or video for each question.
3) Click on the edit button and then go to the appropriate question and paste your answer below it. Sign your contribution with your first name and last initial and TEAM COLOR
4) Save the page by selecting "Save with " from the Save dropdown. Enter a comment (e.g. "I answered chp 26 question 3" - Tom S.) then click Save.
2. How does an electron microscope work and what is the difference between a scanning and transmission electron microscope?
the electron microscope (EM) focuses a beam of elcetrons through the speciemen or onto the surface. the resolution is invrersley related to the wavelength of the radiation a microscope uses for imaging. an electron beam has a shorter wavelenght then visible light, and can achieve a resolution of .002 nm, which means it can see as small as a carbon atom. SEM and TEM are useful for detailed study of the specimens' surface. the scanning electron mircroscope scans the specimen, which is usually covered in gold layer, and it then takes a image of the topography of it. the SEM has a great depth field and the image appears in 3 dimentional, while the transmission microscope can be used for mor e photographic film, or viewing on a screen.
Alecia Seliga
3. Describe the process and purpose of cell fractionation.
The goal of cell fractionation is to take cells apart and separate the major organelles from one another. The centrifuge is used to do this. It enables the researcher to prepare specific components of cells in bulk quantity to study their composition and functions.
Ryan H
4. Label the prokaryotic cell below – list structure and function.
Pili - Attachment structure on the surface of some prokaryotes.
Nucleoid - Region where the cell's DNA is located (not enclosed).
Ribosomes - organelles that synthesize proteins.
Plasma Membrane - Membrane enclosing the cytoplasm.
Capsule - Jelly-like outer coating of many prokaryotes.
Flagella - Locomotion organelles of some bacteria. (Sperm)
- Chris Asimos
5. Why is surface area to volume such an important concept as it applies to the size of a cell?
There is a correlation between size and function. The area is proportional to a linear dimension squared, compared to the volume which is proportional to the linear demension cubed. The smaller it is, the greater the ratio of surface area to volume. Each organelle is the correct size for the cell and the organell's task.
Tyler H
6. For each of the structures below – note the specific structure and the function of the organelle or part of the organelle. The important concept is to note how the specific structure allows for the specific function to be accomplished. Include a picture/video for each
a. Nucleus:
The nucleus is the center of the cell which holds the majority of the genes and DNA of each cell.
-Sam B
i. Nuclear envelope:
The nuclear envelope of the cell has a double membrane which encloses the nucleus. The nuclear envolpe is covered in pores to allow certain substances in and out of the nucleus. It is continuous with the endoplasmic reticulum.
-Sam B
ii. Nuclear lamina:
The nuclear lamina is a netlike string of proteins filamentsthat maintain the shape of the nucleus. The lamina mechanically supports the nuclear envelope with its structure.
-Sam B
iii. Chromosomes:
Chromosomes are discrete, distinct units of DNA that carry genetic information. They are made up of chromatin, neatly packaged into specific orders.
-Sam B
iv. Chromatin- the complex of DNA and protein that makes up a eukaroyotic chromosome. when the cell is not dividing, chromatin exists as a mass of very long thin fibers that are not visible with a light microcope.
Alecia Seliga
v. Nucleolus:
The nucleolus is a mass of densely stained granules and fibers adjoining part of the chromatin. The nucleolis is the dense center of the nucleus physically holding the majority of the genes of the cell.
-Sam B
6 b. Ribosomes:
Ribosomes are molecules made up of chromosomal DNA and proteins. They carry out all protein synthesis for cells. Cell that require many proteins will have many ribosomes in order to spread out the task of each ribosome, and create efficient, productive proteins within each cell for their specific function.
-Sam B
6 c. Endoplasmic reticulum- It is a network of membrane that accounts for more than half of the eukaryotic cells. It has membranous tubules and cisternae, which are sacs that serve as a “reservoir for substances.” It is continuous with the nuclear envelope.
i. Smooth ER- The surface of the Smooth ER lacks ribosomes.
-Some of the metabolical processes that the Smooth ER is part of are the making of lipids. Some lipids that the SER makes are oils, phosphates, and steroids.
- It is also part of the metabolism of carbohydrates.
- It is also part of the detoxification of drugs and poisons. A Hydroxyl group is added in order to make it more soluble. The liver cells would have more SER.
-In muscle cells the Smooth ER stores calcium.
- Fernanda R.
ii. Rough ER is an interconnected system of tubules and vesicles within eukaryotic cells. Its surface is full of ribosomes.
The Rough ER synthesizes proteins and then ships them out through transport vesicles.
Ashley A
6 d. Golgi Apparatus (looks like the ER)
The Golgi processes proteins from the ER mainly through glycosylation (adding sugar to the proteins). They are packaged through secretory vesicles to their destination.
These proteins will most likely be used in the plasma membrane, in lysosomes, or secreted by digestive enzymes.
Ashley A
6 e. Lysosomes are sacs that contain enzymes at high pH levels. When an organelle in the cell gets damaged, a vesicle is placed around it and the lysosomes merge with that vesicle and recycle the organelle. The same occurs when a food vacuole is introduced to the cell. If too many lysosomes break open in a cell by accident, the cell will digest itself completely.
-Josh S.
6 f.
Vacuoles – A vacuole is a membrane bound organelle. It is present in plant and fugal cells and in some protest, animal and bacterial cells
Food – food vacuoles fuse with a lysosome whose enzymes digest the food. The vacuoles carry out hydrolysis and are formed by phagocytosis.
Contractile- pump access water out of the cell to maintain the appropriate concentration of alts in other molecules
Central w/tonoplast- Tonoplasts are enclosed by the membrane. The central vacuole develops by the coalescence of smaller vacuoles. They derived from the ER and the Golgi app. It is an integral part of a plant cells endomembrane system
- Katie Halbruner :)
6 g. Endomembrane system – overall
It is complex and dynamic. It is in the cell's compartimental organization and flow of membrane lipids and proteins through the various organelles.
Tyler H
6 h. Mitochondria
i. Mitochondrial matrix
ii. Cristae
6
i. Plastids- A family of closely related plant organelles.
i. Amyloplast- Colorless plastids that store starch (amylose), particularly in rods and tubers.
ii. Chromoplast- Have pigments that give fruit and flowers their orange and yellow hues. They also contain green pigment called chlorophyll.
iii. Chloroplast (thylakoids & stroma) - Found only in plant cells. They are sites of photosynthesis where converts solar energy to chemical energy by absorbing sunlight. Thylakoids are flattened membrane sacs inside chloroplast used to convert light energy to chemical engery. The stroma is the fluid of the chloroplast surrounding the thylakoids membrane; it is involved in the synthesis of organic molecules from carbon dioxide and water.
-Mike G
6 j. peroxisomes
An organelle with various specialized metabolic functions. It produces hydrogen peroxide.
-Mike G
6 k. cytoskeleton – pay careful attention to the details in this section
A network of fibers extending throughout the cytoplasm. It plays an important role in organizing the structures and activites of the cell. It is composed of three types of molecular structures: Microtubules, Microfilaments, and Intermediate Filaments.
-Mike G
i. microtubules- Hollow tubes that maintain cell shape, cell mobility, chromosome movement in cell division, organelle movement.
1. centrosomes- microtubles grow out of them, located near the nucleus, responsible for compression and resistance.
centrioles- 9 sets of triple microtubules arranged in a ring, used in cellular division and cell organization
2. cilia- many short hair like structures, move like oars
flagella- few long hair like structures, move together in the same direction
basal body- base of the cilia and flagella grows out of centrioles
3. dynein walking- Large protein, made up of polypeptides, cause the bending movement of cilia and flagella, powered by ATP.
ii. microfilaments- are solid rods about 7nm in diameter present in all eukaryote cells, they bear tension, help support shape, transports materials across the plasma membrane and cell mobility.
1. actin- globular protein
in the cell:
muscle contraction
cell mobility
cell division
2. myosin- protein that acts as a motor protein by beams of projection (arms) that "walk" along the actin filaments, causes cell contraction.
3. pseudopodia- extends and contracts through the reversible assembly of actin subunits into micro filaments.
4. cytoplasmic streaming- Circular flow of cytoplasm within a cell, speeds the distribution of materials within the cell.
iii. intermediate filaments-large in diameter, specialized for bearing tension located in the cytoskeleton.
Taihlor C
6 L.
Cell walls- Cell walls are extracellular structures of plant cells, which seperate them from animal cells. Cell walls help to protect the plan cell, maintain its shape and prevent excess uptake of water.
i. Primary cell wall- (Young plants) A primary cell wall is located just beyond the plasma membrane; it is a flexible extracellular matrix.
ii. Middle lamella- Composed of sticky polysaccharides called pectins. Middle lamella is intercellular material which is between primary walls of adjacent cells.
iii. Secondary cell wall- (Adult plants) A secondary cell wall is located between the primary cell wall and the plasma membrane. It contains several laminated layers including a durable matrix for protection and support. Mostly made from cellulose.
-Dahlia M
6M
a. Extracellular matrix- a.k.a. E.C.M. A layer outside of animal cells rich in glycoproteins. Constant source of proteins for cells.
i. Collagen- glycoprotein that makes strong fibrous layer around the cell.
ii. Proteoglycans- weaving glycoproteins that support collagen. Mostly made of sugars.
iii. Fibronectin- glycoprotein that binds the cell to the E.C.M.
iv. Integrins- receptors in the cell membrane that the fibronectins attach to. Act like anchors on a ship: hold the E.C.M. in place. Attach to cytoskeleton on the other side. Takes in information from E.C.M. and send it to the cell.
Below: The horrors of collagen abuse :O
6 n. What are intercellular junctions and why are they important?
Intercellular junctions are tight junctions, desmosomes, and gab junctions. They are important because they keep cells together like a lock.
-Amy D
6 o. Contrast plasmodesmata, tight junctions, desmosomes, and gap junctions.
Plasmodesmata are channels contained within the plant cell wall. Cytosol to pass through the plasmodesmata and connect the chemical environments of adjacent cells, unifying most of the plant into one living continuum. Water and mall solutes can from one cell to the other using these channels.
Tight junctions prevent fluid from moving across a layer of cells. At tight junctions, the membrane of neighboring cells are very tightly pressed against each other, preventing leakages.
-Alina Dyak
PLASMODESMATA
TIGHT JUNCTIONS
-Alina Dyak
The idea of desmosomes is like the glue that holds cells together, they fasten the cells together. This is like a cell to cell adhesion to one of each other, a way to think about it is from the greek meaning “desmos” means band, and “soma” means body, so the two cell bodies are banded together by desmosomes. Whereas gap junctions leave a space in between for the sharing of the cells, they use cytoplasmic channels adjacent from the other cell. With the use of the cytoplasmic connections allows for ions and molecules to pass freely from cell to cell.
-Brett Sutow
^^Desmosomes
^^^Gap Junctions